Method of cutting blanks.



i E. s'. STILBS.

METHOD OF GUTTING BLANKS.

AHLIQATTIQN FILED JUNE 12.' 190e.

927,293. Patented July 6,1909.

Y III! n /C/ mouw. n. Gamm om PmTo-Llvmcmmews. wnmaou n c PATENT OFFICE.

EDMUND S. STILES, OF RIVERSIDE, ILLINOIS.

METHOD OF CUTTING BLANKS.

To all whom it may concern:

Be it known that I, EDMUND S. STILns, a citizen of the United States,residing at Riverside, in the county of Cook and State of Illinois, haveinvented a certain new and useful Method of Cutting Blanks, of which thefollowing is a specification.

My invention is adapted primarily to the cutting of substantiallycircular blanks from sheets of metal, strawboard, fiber or othermaterial employed for the manufacture of the ends or covers of cans andsimilar containers.

The object of the invention is to provide a `method by which the blanksmay be obtained with the greatest rapidity and greatest economy ofmaterial where the feeding is done by hand and the blanks are producedone at a time.

To facilitate description of my method I will refer to the accompanyingdrawings, in which:

Figure l represents the sheet after the first step in the process hasbeen completed. Fig. 2 represents the sheet during the second and finalstep in the process after three blanks have been cut and Fig. 3 reresents a sheet after the entire sheet has 1geen once subjected to theprocess and said second step is in the course of repetition.

It is well known of course that a greater number of circular blanks maybe produced from a given sheet of material if the blanks be staggeredthan if they be arranged in rows extending at right angles to eachother. This principle has been recognized in gang punches which areusually arranged with the punches staggered. But for different reasons,in much of the present day manufacture the blanks are punched one at atime in rows and the feeding is done by hand. Under such circumstancesthe second row of apertures from which the blanks are produced usuallybear an indefinite relationship to the iirst row of apertures; andsometimes in the trade the process is facilitated by employing narrowsheets or strips just wide enough to produce two rows of blanks, theproper guiding of the strip being accomplished by reversing the stripend for en d after the first row of apertures has been cut, thus usingfor each row the smooth edge of the strip, which may travel along theside guide of the machine.

The spacing between any two apertures in a row is effected by alwaysfeeding the strip forward until the edge of the last apertureSpecification of Letters Patent.

Application led .Tune 12, 1908.

Patented July 6, 1909.

Serial No. 438,134.

contacts the gage or stop which is always provided in single acting handfed punching machines. For various reasons, however, (among them wasteof material in making round holes fit rectangular sheets, and thenecessity for reversal of the sheet where side guides are employed,) theemployment of narrow strips of material from which only two rows ofblanks can be cut has disadvantages which are eliminated by my method;for as the result of this method, not only may wide sheets of materialbe employed, but the necessity for reversing the sheet is eliminated andthe apertures are located accurately and rapidly without es ecial careon the part of the-operator. The method by which these desiderata areaccomplished is as follows: A sheet of metal, strawboard, fiber or othermaterial from which the blanks are to be produced, is procured of aWidth capable of furnishing several, preferably eight or nine, rows ofblanks. This sheet, represented by a in each of the figures, is then cutin such a manner as to form gage-abutting edges t, b1, b2, etc. havinglocated between them other gageabutting edges c, c1, c2, etc. Theseedges are located at a distance apart less than the diameter of theblanks to be produced, the amount depending upon what margin may besafely left under the conditions of malinfacture. Considered in thedirection of feed, the different gage-abutting edges differ from theones on either side of them by one half the feeding distance. Thisfeeding distance is equal to the diameter of the blank plus the scrapwhich the manufacturer decides to leave for safety under thecircumstances and conditions of manufacture. After the sheets are thusprepared, the operator, standing usually behind the sheet at the edge dthereof, places the sheet with its right edge c in contact with the sideguide and the forward gage abutting-edge b in contact with the feedinggage or stop 71,. After the punch has descended and removed a blank theoperator advances the sheet until the inner edge of the resultingaperture contacts gage 7i. This process is repeated until the entire rowof apertures has been formed. During the punching of the first row ofapertures the sheet is automatically sheared bythe punch press along theline r-c Fig. 2, the shear agging behind the punch about one or twoholes as indicated in Fig. 2. As the shearing action thus lags slightlybehind the punching action it will of course be necessary for theoperator to feed the sheet a short distance farther after the punch hasfinished with it in order that the shear may complete the cutting of thesheet, and form a new guiding edge for the side guide f. This line ofcut c-c passes through the apertures from which the blanks have beenremoved and consequently the new cutting edge is serrated. Theseserrations or teeth j are, in a sense, the source from which the savingis made possible, because as the next gageabutting edge cis advanced onehalf the feeding distance the new aperture comes between two adjacentapertures of a preceding row.

After the first row of blanks have been removed and the new guiding edge7c 7c formed in a manner thus described, the second step in the processis again repeated, the serrations slipping along the side of the gage fin the manner indicated in Fig. 3. The opera-tion is repeated over andover until the entire sheet has been consumed. By proceeding in thismanner there is practically no waste material except such amount ofscrap as is practically always necessary even when a gang punch isemployed. The sheet need never be reversed and the successive punchingoperations may take place in rapid succession Without requiring greatskill on the part of the operator and without running the risk of havingthe apertures inaccurately placed. This, it will be remembered, isaccomplished in a process in which not only is the feeding done by handbut the stamping is done one blank at a time.

Having thus described my invention, What I claim as new, and desire tosecure by Letters Patent, is-

The method of producing substantially circular blanks from sheets ofmetal or other material consisting in first preparing a sheet by forminggageeabutting edges differing each from the next by one half the feedingdistance; said edges being located at a distance apart less than thediameter of the blank to be cut; then punching a row of blanks one at atime, and simultaneously cutting the sheet upon a line parallel to thedirection of feed to form a new guiding edge, said linel passing throughthe apertures formed by the removal of the first row of blanks,substantially as described.

In witness whereof, l have hereunto sub- -scribed my name in thepresence of two wit nesses.

EDMUND S. STILES. vWitnesses 2 HOWARD M. Cox, C. J. CI-IRIsToFFnL.

